/* 
 * Copyright (c) 2016 Lammert Bies
 * Copyright (c) 2013-2016 the Civetweb developers
 * Copyright (c) 2004-2013 Sergey Lyubka
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * ============
 * Release: 2.0
 */

#include "httplib_main.h"

/*
 * void XX_httplib_remove_double_dots_and_double_slashes( char *s );
 *
 * The function XX_httplib_remove_double_dots_and_double_slashes() removes
 * '..' instances and excessive '/' and `\` characters to protext against
 * directory disclosure attacks.
 */

void XX_httplib_remove_double_dots_and_double_slashes( char *s ) {

	char *p;

	p = s;

	while ( s[0] == '.'  &&  s[1] == '.' ) s++;

	while ( *s != '\0' ) {

		*p++ = *s++;

		if ( s[-1] == '/'  ||  s[-1] == '\\' ) {

			/*
			 * Skip all following slashes, backslashes and double-dots
			 */

			while ( s[0] != '\0' ) {

				if      ( s[0] == '/'  ||  s[0] == '\\' ) s++;
				else if ( s[0] == '.'  &&  s[1] == '.'  ) s += 2;
				else break;
			}
		}
	}

	*p = '\0';

}  /* XX_httplib_remove_double_dots_and_double_slashes */
